Background In the era of modern anti-rheumatic therapy, it is now possible to contemplate the idea of clinical remission in patients with psoriatic arthritis (PsA)¹. It is however unknown whether patients in clinical remission can stop methotrexate (MTX) or tumor necrosis factor inhibitor (TNFi) treatment².

Objectives To investigate drug-free remission in patients with PsA and potential predictors for flare.

Methods Patients with PsA in remission (no musculoskeletal symptoms, no or minimal skin/nail disease) for at least 6 months were included. At baseline the following parameters were assessed: age, sex, BMI, disease duration, duration of remission, swollen joint count, tender joint count, VAS-pain, VAS-global, NAPSI, PASI, MASES, LDI, HAQ-DI, SF-36, FACIT-F, anti-rheumatic therapy (MTX, TNFi), ESR and CRP. In addition, ultrasound of 20 joints and 20 enthesis was performed. After discontinuation of therapy at day 1, patients were followed for 6 months for the occurrence of flares.

Results 26 patients (20 males, 6 females) were enrolled. Mean ± SD age was 55 ± 14 years, mean ± SD disease duration was 6.1 ± 6.2 years, mean ± SD duration of remission was 23.9 ± 23.7 months. 15 patients received MTX monotherapy, 11 were treated with TNFi (6 in combination with MTX). We observed a high incidence of flares (76.9%, N= 20), with flares occurring relatively early (74.50 ± 50.79 days). There was no difference in flare rates between the MTX and TNFi groups. Due to our low number of patients, predictors of flare could not be determined but some important trends were observed. Male patients were more likely to flare (OR=18.00; [95%CI: 1.92-168.99]; p=0.011); patients with lower BMI (U=33.50, z=-1.61, p=0.107, r=0.32) and longer disease duration (U=35.50, z=-1.51, p=0.132, r=0.30) showed medium effect trends to flare. Further, presence of calcifications at the enthesial sites was associated with flares (U=33.50, z=-1.50, p=0.133, r=0.30).

Conclusions This study showed a high incidence of flare in patients with PsA after discontinuing therapy. Although remission in PsA is an obtainable goal, drug-free remission may not be realistic for the majority of patients. Our study suggests that some baseline characteristics, such as male sex, low BMI, longer disease duration and enthesial calcifications predict flares of PsA after discontinuation of anti-rheumatic therapy.

References Kavanaugh A., Fransen J., Defining remission in psoriatic arthritis. Clin Exp Rheumatol 2006: 24(Suppl. 43): S83-S87.

Saber TP, et al., Remission in psoriatic arthritis: is it possible and how can it be predicted? Arthritis Research & Therapy 2010, 12:R94.

Disclosure of Interest None Declared